Field of the Invention
The present disclosure relates generally to memory arrays, and more specifically to a random-access memory array including modified memory cells that enable read-only memory to be embedded within the memory array.
Description of the Related Art
Counterfeiting is costing integrated circuit (IC) design companies a substantial amount of revenue and often causes product-name and customer loyalty damage. There are several different types of counterfeiting semiconductor products, such as recycling (in which parts are pulled off boards and improperly resold), re-marketing (in which the counterfeiter improperly repackages parts from another and resells the repackaged parts as their own), manufacturing overproduction (in which a semiconductor manufacturer over-produces and sells otherwise legitimate devices in violation of their agreement), and cloning (in which a hacker reverse-engineers and manufactures and sells the re-engineered parts often in violation of the legitimate owner's intellectual property rights).
Cloning is the process of extracting the layout and design of an IC, generating a corresponding mask or database of the extracted information, and fabricating a cloned IC intended to copy or match the original function to the extent possible. Part of the process includes exposing layers or devices of the IC and inspecting the exposed portions using a high-powered microscope or the like. Cloning may include extracting the code of a ROM chip or embedded ROM. Although many policing or legal methods may be employed to reduce counterfeiting, it is particularly advantageous if the part or manufacturing process itself is configured to reduce or otherwise prevent cloning.